Sorry but I'm going to be harsh again here. Your previous experience with customer service counts for nothing now that you're an Airbnb host.
Let me give you a case in point; I started hosting in the 1980s (a traditional B & B) and have hosted ever since including our own STR which we now have on Airbnb. Therefore I think that I have enough experience of 'old-style' hosting and Airbnb but believe me. hosting on Airbnb is unlike anything you've ever done before.
You have had a guest who was enough of a problem for you that you were compelled to join this forum and post at length about your woes with this person. And now you have given him a good review. That is not being a responsible host.
I'm sure that it's because you're new and you don't understand the system but as far as you saying:
Yes, it's in your past. But what about future hosts? I'm sure that you don't mean to be selfish but it comes across that way when you say that it's over for you. It implies that you only care about yourself and not the rest of us. We hosts have a duty to report accurately about our guests.
As you're new you probably didn't realise this but it's essential to the way that Airbnb works. Review guests factually and honestly to allow future hosts to make their hosting decisions wisely.